The present invention relates to agriculture, and, more particularly, to grain crop treatment and can be used on farms and in the grain crops-elevator industry.
Methods and devices are known for grain crop storage, based on the use of ozone-enriched air, including heated air for drying, disinfecting, detoxification, storing grain crops, and pretreating seeds before sowing. Also, corresponding technical solutions for realization of the above mentioned methods is known.
It is well known that the greatest quantitative losses of grain crops and seeds in the moist state are caused by their spoilage during their temporary keeping on grain-floors after harvesting and preparing for storage. In the Ukraine and other CIS countries the losses reach 25% of gross grain harvest because of insufficient quantity of drying facilities, the high cost of equipment and power, and the low quality of processes for drying grain crops and seeds, as well as the absence of effective methods for disinfecting and detoxification of damaged grain and seeds.
It is possible to decrease the spoilage of moist grain and seeds if the aeration system allows constant and uniform drying of grains and seeds, even if the process is slow. This is possible for a comparatively thin (2 m-3 m) layer of grains and seeds. The reliability of this slow process for drying grain and seeds would be higher if the grain and seeds, simultaneously with drying, were subjected to treatment with a disinfectant prepared in the form of an ozone and air mixture.
A method for drying seeds of grain cultures is known, in which to intensify the process of drying and decrease its power consumption, the ozone and air mixture, with an ozone concentration of 2 mg/m3-1.0 mg/m3, is passed through the layer of seeds. This method is based on intensification of the water evaporation process inside the seeds under ozone action. While interacting with the seeds, ozone starts decomposing in accordance with the scheme 2O3=3O2+68 kcal/mol. Generated oxygen assists in improving the oxidizing processes inside the seeds and, as a result, provides for rising temperature in the seeds and diffusion of moisture from the seeds. One product of the ozone and seeds interaction is hydrogen peroxide, which is used as a bacterial agent for detoxification of seeds.
It has been found by researchers that adding ozone accelerates the drying process by no more than by 5%, which is insufficient to use it as a drying agent. At the same time, the process of drying is considerably shortened with an increase in temperature and airflow rate blowing through the grain and seeds. Ozone is an effective disinfectant, which suppresses action of microorganisms that cause spoilage of grain and seeds.
Seed sterilization methods based on heating and moisturizing of the seeds by vapor and water are known. The subsequent process of drying seeds is performed by microwaves and ozone, while the seeds are moving on a conveyor.
Seed treatment based on lowering the pressure in the storehouses with subsequent supply of the agent into them is also known.
The use of ozone for intensification of the process of grain and seeds drying and for elimination pests and diseases is also well known.
Fungus inactivation by ozone, which is more efficiently performed at higher values of temperature and humidity, has been studied. The level of initial humidity has no influence on the germination of barley seeds, and the high doses of ozone lower the index.
The influence of treatment by ozone in grain and seeds quality and germination energy has also been studied. Some lowering of the indices after treatment of grain and seeds by ozone was noted.
The problem of efficiency of the ozone used as a fumigant in the case of grain storage has also been explored. The treatment of 8.3 t grain by ozone at a concentration of 107 mg/m3 during three days caused death of 92%-100% of storehouse pests. The basic characteristics of the grain did not worsen.
Studies have shown that the period of grains and seeds storage lengthens in a sour environment due to the lowering of their biological activity.
The fumigation of grains and seeds by a thermal dryer equipped with a system for ozone sterilization of the grain in the seeds is known. The system is arranged before the discharge opening of the dryer.
The above mentioned solutions show that the use of ozone as a fumigant is more efficient, safe and not as expensive as the application of toxic chemicals. As a disinfectant, ozone removes a microbial cause of spoilage of grains seeds, and because of its high solubility in water, it is especially active in a moist environment. Ozone application is also effective for elimination of storehouse pests.
A method of detoxification (reanimation) of moist grain and seeds having first signs of spoilage (mold) is known. As a rule, special toxins accumulate in a mass of grain and seeds, which in the case of concentrations exceeding 5 mg per 1 kg of the grain and seeds lead to diseases, which affect not only animals and birds, but also people.
Nowadays, in order to provide detoxification of grain and seeds, a method of thermal treatment is mainly utilized. This method prevents subsequent development of microflora, however, it does not destroy harmful toxins that have already been generated.
Technology for storage of grains and seeds spoiled by storehouse pests has been studied. The loss of grain vital function reached 3%-5%. Pesticides used for grain and seed disinfection caused contamination of grain by the remaining chemical substance. The method of ozone disinfection in accordance with the results of the research, provided for effective and environmentally clean protection of the grain and seeds while maintaining their organoleptic and physical and chemical properties. The method efficiently destroyed mold toxins and provided sterilization of insects.
A method for pretreatment of seeds before sawing is known, in which an ozone and air mixture is used as a growth-stimulating substance. The method is carried out in clamps on a field ground with the use of a compressor, ozonizer, and plastic hoses equipped with injectors being are arranged inside bulks. This technology is simple, however, it does not provide an even distribution or maintenance of ozone concentration inside the bulk, or adjustment of air temperature in the interseeds space and seed humidity, which stimulates ozone activity. These disadvantages of the disclosed method prevent the achievement of expected stabile results.
The advantages of ozone application for treatment of grain and seeds are determined by a complex action of its drying and bactericidal properties, and also by its ability to stimulate the enzymatic system of seeds promoting productivity.
However, despite acceptable ecological characteristics and high properties as a disinfectant, ozone has not been practically used on an industrial scale since there have been no technical solutions related to ozone delivery to each level of grain and seeds bulks without changing the initial characteristics of ozone. It is explained by a short period (about 40 minutes) of ozone life and its high specific gravity, in comparison with air.
It is believed that the mechanism of spoilage of moist grain and seeds resides in the reduction of oxygen consumption with anaerobic breathing, which begins the irreversible processes of fermentation. Ozone is capable of reanimating grain and seeds by penetrating inside grains due to its oxidizing properties and supplying oxygen, which is necessary for renewal of the vital functions of grain and seeds.
A method for treatment of grain seeds, which is the closest to the method in accordance with the present invention, includes air drying of the grain and seeds with transverse blowing through the grain and seeds bulk placed in a bunker by an ozone and air mixture, including a mixture that is heated. The ozone and air mixture is delivered through a central perforated pipe. It has been shown that the use of ozone and air mixture for drying grain seeds is more effective than with surrounding air. The twelve hour period of the process with the use of the ozone and air mixture, with an ozone concentration of 3 mg/m3-5 mg/m3, reduces the time of drying by 20%. It has been found that heating up the ozone and air mixture results in considerable acceleration of the drying process when compared to the active aeration (ventilation) process with external (ambient) air. Active aeration with the use of ambient air heated to 3° C.-6° C. at a feeding flow rate of about 100 m3/h-250 m3/h per 1 ton reduces the time of drying by a 17-18%.
The transverse (horizontal) blowing through grain and seeds in bulk as well as the use of the ozone and air mixture for intensification of drying process has several disadvantages. It is not possible to provide stability of temperature and relative humidity of gas due to direct contact of grain and seeds with ambient air through an opening in the perforated case of the dryer. The treatment of grain and seeds is uneven because of different values of air flow rates per bulk height. Energy consumption is increased because of an insufficient degree of controlling the layer-by-layer drying process of the bulk. The maximum permissible level of ozone concentration around the dryer can be exceeded because of uncontrolled exhaust of ozone through perforations in the dryer case and because of the lowered functional possibilities of ozone under such conditions. Furthermore, the system reliability is decreased due to the use of a piston that moves inside the air-distributing device.
Structural solutions for bunkers with a standard aeration system (in the direction from below to top) and a perforated bunker with transverse (horizontal) blowing through the bulk are known.
In the marketplace there are well known intrasilo thermal dryers. An advantage of these dryers is their relatively high speed of drying. However, they also have the following disadvantages. They are characterized by high power consumption to provide high temperature drying and subsequent cooling of grain and seeds. They require a high cost of power media to be used, such as natural gas or diesel fuel. Furthermore, grain and seeds and the environment are contaminated by combustion products of the power media. Cracking and spoilage of grain and seeds are possible because of temperature drops resulting from high heating and sharp cooling. The quality of grain and seeds drying is insufficient. The dryer has high manufacturing and maintenance cost, and there are also fire-hazards during drying of oil-bearing cultures.
A bunker having a perforated shell case is known. The bunker has a cone-shaped roof upper part and a lower part with a discharging bottom whereon there is mounted a perforated and distributing device equipped with an inner piston regulator for discharging air. Such a bunker with a perforated case is penetrable for rain. Grain and seeds when inside such a bunker are sensitive to changes in temperature and environmental humidity. The bunker is used only in a closed compartment for storage of a grain and seeds lot of about 40 t.
A prototype silo device for storing grain and seeds includes a case composed of panels, a cone-shaped roof, and a bottom fastened in the silo axle cylinder container, which has perforations and is connected with a ventilator by a pipeline. The pipeline is provided with a branch pipe for coupling the pipeline with a source for feeding a gaseous fumigant. The silo provides for aeration of grain and seeds according to a traditional scheme from bottom to top by means of air supplied in its lower part. This technical solution also provides for a possibility of disinfection of grain and seeds.
This traditional system of aeration has some disadvantages including high energy consumption because of the use of a high power ventilator for blowing medium through the grain and seeds column from the bottom to the top, so that in each subsequent zone of grain and seed bulk along the silo height the air or fumigant enters with characteristics which have been substantially changed as compared to the initial characteristics. Another disadvantage includes accidental “cavitations” being formed in the grain and seeds bulk as “channels” through which air further moves, resulting in some areas of bulk (standard areas) that have not been treated by the air stream outgrowing into hearths of self-heating and spoilage of the grain and seeds. Still another disadvantage is the low speed of removing moisture which moves with air through the whole column of grain and seeds and does not correspond to the criteria of drying requirements.
Fumigation of grain and seeds in this case is also not effective. In the first turn, the fumigation concerns such an environmentally clean and effective fumigant, ozone, which in the moist environment quickly, during 30-40 minutes, decomposes and does not provide even treatment of all levels of bulk.